If you slash a sidewall its done from the outside – no?

So why would a tubless sidewall be more susceptable to getting slashed than the same tyre but run with a tube?

Incidentally I run non-tubeless tyres on ZTR Flows and ghettoed WTB Laserdiscs and in a year of doing so I haven't managed to slash one. Not the most agressive rider but I'd podium for clumsiest.

So why would a tubless sidewall be more susceptable to getting slashed than the same tyre but run with a tube?

It isn't IMHO.

tubeless sidewalls are normally a bit thicker, hence less susceptible but (as well as to stop slow leaks) they do that because a slashed sidewall is a bit harder to sort when tubeless than tubed

(isn't it?)

(ed: and, I suppose running lower pressures might just mean the sidewall bowing out further & being more exposed to rocks etc while riding ?)

Depends where you ride. I rode over roots on natural trails all winter on my Michelins, no trouble. One ride up in Torridon and they were slashed to bits.

a slashed sidewall is a bit harder to sort when tubeless than tubed

Is it?

tubeless sidewalls are normally a bit thicker, hence less susceptible but (as well as to stop slow leaks) they do that because a slashed sidewall is a bit harder to sort when tubeless than tubed

They do that to give extra support as the tyre doesnt have a tube to help. A tubeless is only harder to sort as you have to remove the tubeless valve…hardly troublesome!

People always seem to talk about tubeless tyres getting slashed, never tubed…think this is people seem to think that running tubeless means they can run uber low psi…hmm, for me the benefit is rolling resistance with same psi (i like my rims!) and better feel.

Been running normal maxxis kevlar single ply for just under a year now with no slashing issues (although weekend gone i did pull the rear tyre compleatly off the rim at ~30psi…just got me a 2bliss for the tighter bead).

I've never slashed a [normal tyre] tubeless setup

TBH – I would think the lower pressures make it less susceptible as the wall will distort a little more than higher PSI tyres
Something at high pressure doesn't take a lot of persuading to split if you touch it with something sharp, lower pressures give you more resistance to that sort of damage

In 10 years of riding I've slashed one tubed tyre setup, and no tubeless tyres.

I would think twice about running the single ply maxxis I've got at the moment if I was going somewhere rocky. I'd just put UST of LUST on instead.

a slashed sidewall is a bit harder to sort when tubeless than tubed

Is it?

Well, I'm guessing here, hence the "isn't it?" aspect…

As somebody up there said, there's the extra "support" of a tube inside so a small rip or a longer hole held together only by some carcass threads can be ridden home either just using a new/patched tube or letting the tube compress a temp patch/toothpaste tube etc onto the inner sidewall, holding it in place. Then you can get home, clean up all the dust (lol) or mud and do a proper repair.

Tubeless, if ripped beyond the help of jizz, you'd have to clean off all the jizz/any mud etc and properly fit a patch that's fully adherent while out & about (or you carry all the same spares as you would for tubed tyres, of course).

Also, I suppose, if the sidewall is thicker exactly because there's no tube and more support is needed (as was said up there ^ ), then the tubeless repair might be under more stress & more likely to fail while riding and – regardless of the likelihood – a further failure of the repair would be more instantly unrideable

Never having done either for a big rip, I suspect the latter is more of a ballache

I ride tubeless now & haven't split a sidewall but have cut the treaded bit of the carcass on 2 tyres – small enough to get me home with a tube though (but that means I'm having to carry one as a contingency plan).
I believe that the sidewalls are thicker mostly to make them airtight but also to make a rip less likely in the 1st place. It's a LOT more of a pain to put a tube into a used tubeless tyre because of the jizz and more importantly, all the little thorns/flints that the tubeless tolerates fine but will bugger up your tube in a matter of yards. So you have to prat about digging out little bits from the inside of a jizzy tyre before you can shove in a tube. On a tubed tyre there's usually only one to find and it's in a dry tyre.

[edit: I think the reason people talk about tubeless tyres and "slashes" etc is because they tolerate minor damage so well and so only become noticed when a big issue ( 😉 ) arises and the tyre fails]

i ran an ADvantage for all of 20mins before i ripped the sidewall.